JPS5859460A - Liquid developer for use in electrostatic image - Google Patents

Abstract

PURPOSE:To obtain a developer capable of easily forming a high density image, by dispersing into a liquid carrier of an aliphatic hydrocarbon, insoluble resin particles, a resin obtained by suspension polymerization in the liquid carrier, wax, etc., and a rubber type resin, etc. soluble in the liquid carrier. CONSTITUTION:Resin particles (component A) substantially insoluble in a liquid carrier of a petroleum type aliphatic hydrocarbon, a resin (component B) obtained by suspension polymerization in the liquid carrier, wax of polyolefin resin particles (component C), and a rubber type resin (component D) are dispersed into the liquid carrier in 0.5-5 A/B weight ratio, and 0.2-2 (A+B)/C weight ratio, and 1-4 A/D weight ratio, and a colorant is added to either of the components A and B. As the component D, for example, vinyltoluene-butadiene copolymer, styrene-butadiene copolymer, butadiene rubber, butyl rubber, etc. are used.

Description

Detailed Description of the Invention Regarding the FP4#i liquid developing agent for silent images of the present invention, a liquid for silent images in which specific toner particles are dispersed in a carrier liquid of a petroleum-based aliphatic hydrocarbon. Regarding toy agents.

Conventionally, many liquid developers for electrostatic images are known, but
Typically, (1) resin particles or colored resin particles substantially insoluble in the carrier liquid are dispersed in a carrier liquid of aromatic hydrocarbon or aliphatic hydrocarbon, (2) the above-mentioned ( 1)
A graft polymer in which the frame part is insoluble in the carrier liquid and the core part is soluble in the carrier liquid is added (% Kosho 54
-35492), (3+the above-mentioned (1) or (2) with a further addition of a polarity control agent), and Hirom.

However, with these liquid developers, if aromatic hydrocarbons are used as the carrier liquid, the carrier liquid adhering to the background of the image receiving paper will emit a very strong odor during fixing. good ventilation, and (1)
) and (2), although the dispersion stability of the toner particles is improved, the transfer of the toner particles to the image-receiving paper is still insufficient and it is difficult to obtain a high-density image. To the east, in the case of item (3) above, there is a cover for developer to adhere to the image area on the photoconductor (photoconductor for single-child photography) or electrostatic recording medium (swelling of developer).
In addition to this, there is a drawback that the toner particles have a large sedimentation property and are unstable in practical use.

An object of the present invention is to provide a liquid developer for electrostatic images that is free from the above-mentioned defects and can easily produce images of high density and particularly excellent clarity. Another object of the present invention is to provide a liquid developer for electrostatic images that has a particularly good adhesion amount to an image area on a photoreceptor or an electrostatic recording medium.

That is, the liquid developer for electrostatic images of the present invention comprises suspension polymerization of resin particles (component A) substantially insoluble in the carrier liquid in a petroleum-based aliphatic hydrocarbon carrier liquid. The obtained resin (component B) and wax or polyolefin resin particles (
C component) and a rubber-based resin (D component) soluble in the carrier liquid are dispersed, and the weight ratio of these A component to B component (
A/B) is in the range of 0.5 to 5, and the weight ratio of the sum of A and B components (A + B) to C component (A+B/C) is 0.
2-2, the weight ratio (k/D) of A component and D component is 1-2.
4, and the colorant is at least component A or component V.
It is characterized by being contained in the iB component.

To explain the present invention in more detail below, the toner particles in the present @8 developer are composed of the above-mentioned components A and B.
component, C component, D component, and coloring agent (dye/pigment). The A component here may be composed of a resin alone, or may be a colorant (for example, Carzen Black) dispersed in an rI'i resin, or a colorant coated with a resin. There may be.

The resin used in component A is selected from those that are substantially insoluble in petroleum-based aliphatic hydrocarbons (carrier liquid). Examples of such resins include resins containing at least 70 mol% of styrene, and epoxy resins. , phenol resin, rosin-modified polyester resin, rosin-modified maleic acid resin, rosin-modified phenol resin, thermoplastic polyester resin, coumaron resin, and the like.

The particle size of this human component is preferably about 0.1-10 pna, preferably about 0.3-6 μm.

Component B is suspended in a petroleum-based aliphatic hydrocarbon solvent. This can be broadly classified into Fi2a[a. Types of wjl include %Kokai No. 50-10140, JP-A No. 50-99331, and JP-A-51-12615.
No. 2, %Kokai No. 55-22718, JP-A-55-331
In aliphatic hydrocarbon solvents such as those proposed in publications such as No. 10 and JP-A No. 55-35321,
It is a resin obtained by graft polymerization. for example,
In an aliphatic hydrocarbon solvent, (&) a 7-mer represented by general formula (1) % formula %), acrylic acid, methacrylic acid, 7
Sprinkle with unsaturated carzene such as malic acid, crotonic acid, itaconic acid, maleic acid, or their acid anhydrides, or glycidyl foundations such as glycidyl acrylate and glycidyl methacrylate! (bl) When this polymer contains unsaturated carzene or its acid anhydride as a constituent unit, it is a glycidyl group-containing polymerizable monomer, and this polymer is a glycidyl group-containing polymerizable monomer. When it contains a monomer as a constituent unit, it is subjected to an esterification reaction with unsaturated cardan 11I! or its acid anhydride, and this esterified polymer is combined with mono i- of the following general formula (2) or a polar monomer of the following general formula (2). Examples include those obtained by graft polymerization with a compound.

General formula (2): %Formula% [However, R is hydrogen or -C1(,,yFi-C00Cn
H1B+1 (1≦n≦4).

-OCOCmH1rn+, (1≦m≦6).

Examples of the above-mentioned polar compounds include monomers of the following general formula (3), maleic acid, 7-malic acid, atropic acid, allylamine, vinylamine, aroyl alcohol, vinylsulfonic acid, and pinyl phosphorus [! 0 General formula (3): % formula % [However, R is hydrogen or -CH,,2ke-C00C,H4N (CnH*n++)t, -
C0OH, 7COOC, H40H.

represents. ] As a second type, a resin that is insoluble or poorly soluble in an aliphatic hydrocarbon solvent such as those proposed in JP-A-52-77731 and JP-A-52-127336 is used. soluble at least l
It is a resin that is dissolved in a monomer of cypress and polymerized dropwise into a heated aliphatic hydrocarbon solvent.Resins that are insoluble or sparingly soluble in the aliphatic hydrocarbon solvent include natural resins such as ester gum and hardened rosin; , natural resin modification! Examples include natural resin-modified thermosetting resins such as leic acid resin, natural chill resin, natural resin-modified pentaeryth resin, and epoxy resin.

A seven-mer that constitutes a polymer that can be solvated in the solvent and that can dissolve the resin is represented by the general formula % (an integer of 6 to 20). ] Vinyl monomer shown by (hereinafter referred to as monomer G),
For example, sulfur, lauryl, 2-ethylhexyl or hexyl esters of acrylic acid or methacrylic acid;
~butyl methacrylate; cetyl methacrylate; octyl methacrylate; vinyl stearate and the like.

For this monomer G, glycidyl methacrylate, glycidyl acrylate, propylene glycol monoacrylate, propylene glycol methacrylate, hydroxyethyl methacrylate, acrylonitrile, and methacryl tetranitrile (hereinafter referred to as monomer J) can be used as a mixture of lfi or more. These monomers J are added to monomer G before polymerization of monomer G, or added to the polymerization after polymerization of monomer G and copolymerized. things
Although r-J dissolves the resin that is substantially insoluble in the non-aqueous solvent, when it is polymerized alone, it cannot be solvated in the non-aqueous solvent. The ratio of monomer G to monomer J is generally 70 to 99:30 to 1 degree (weight ratio).

Further, the resin proposed in Japanese Patent Application Laid-open No. 53-54029 can also be used in the present invention as a resin other than the above-mentioned 2aI type.

The B component may or may not contain a colorant, but if the A component does not contain a layer colorant, it must be included.

Component C is added to the 7-mer solution before or during the polymerization of the FiB component, or it is added to a solution in which component B is dispersed in a petroleum-based aliphatic hydrocarbon solvent and heated. Alternatively, wax or polyolefin resin is dissolved in a heated petroleum-based aliphatic hydrocarbon solvent and then cooled to produce fine particulate component C, which is then dispersed with other components in a carrier liquid. Like the B component, the OC component is also more finely particulate than the A component.

Union Carbide (US) DYNI is used as the waxy substance or polyolefin resin that becomes the C component.
102DYNF 102 DYNH102 DYNJ 102 Union Carbide (USA) DYNK
102 Monsite (US) 0RLIZON so
s 116# 7Q5 116 # 50 126 Filituzos (US) MARIJX 1005 9
2 Dupont (US) ALATHON 3 103#
10 96 # 12 84 # 14 80 1 16 95 # 20 86 # 22 84 y 25 96 Allied Chemical (US) AC-Polyethylene 17
02 98# 6&6A 102 z 615 105 Sanyo Chemical Wax 131-P 108#
151-P 107 # 161-p-111 1165-p 107 Sanyo Chemical Pux 171-P 105#
E-20095 Genuine Chemical Paraffin Wax 60-98 Kobayashi Kako Sarashi Beeswax 65 Setanol 80 Mizuben Kako Sarashi Beeswax 65 Steel Chemical Co., Ltd. Frozen 11G is a substitute for O D acid component petroleum-based aliphatic carbonization Hydrogen soluble GoAMm fat)
i, vinyltoluene-butadiene rubber copolymer (up to 60 mol of vinyltoluene), styrene-butadiene rubber copolymer (up to 55 mol% of styrene), butadiene rubber, butyl rubber, etc. , Tsurpuren 235,
Turprene 1204, Plyo //7 Rex 341
7. Examples include those commercially available as Pryoflex 1502.5BR1500, Butyl Rubber HT-1067, Butyl Rubber 68, Ethobutyl 215, Esso Vistaron 4504, Esso Vistaron 3708, Esso Vistanex LM, Esso Vistanex MN%. .

Since component D dissolves slowly in aliphatic hydrocarbons, it is preferable to use a solution that has been pre-prepared as a swollen solution of about 10 to 30% by weight.

In addition, a carrier a (petroleum-based aliphatic hydrocarbons, such as paraffinic or isonorafine-based hydrocarbons, Manufactured by Esso, Isopar H
, Isonose G, Isopar L, Isopar, naphtha scale 6, Tsurpez 100), ligroin, n''''hexane, n-hebutane, 1so-octane, n-octane, carbon tetrachloride, singly or in combination. are used in combination.

In order to actually produce the developer of the present invention, first, the ^ component, B component, C component, and D component of Mayuki are prepared respectively. In this case, B
Components B, C, and D are suspended in a carrier liquid (petroleum-based aliphatic hydrocarbon solvent), and then Component A is added with a foil and dispersed in a Zeel mill to form a concentrated toner. It is advantageous to do so. Similarly, as mentioned above, when adding component C, it is not necessary to prepare it from the beginning, but when adding component B, it is necessary to rub the component so that it is generated in the petroleum aliphatic hydrocarbon solvent at the same time. It's advantageous.

Next, a carrier liquid may be added to the toner to dilute it to an appropriate toner concentration. In this manufacturing process, component A itself is insoluble in the carrier liquid, but due to the presence of component B, it becomes uniformly fractionated in the carrier liquid. The resulting liquid developer has further improved dispersibility, and also has good releasability of the image area toner from the photoreceptor or electrostatic recording medium.

Furthermore, the D component is adsorbed to the particles of the N component, which is a relatively coarse particle, and the C component, which is a relatively fine particle.
The cohesive force between these particles is increased, and dispersion stability is also promoted. This D component is extremely effective in improving the transfer efficiency during toner image transfer, increasing the image density of a copy, and increasing the sharpness, that is, the clarity of the image. Furthermore, the addition of component D also improves footwear.

In addition, in order to maintain this uniform dispersibility and to improve dispersibility, transfer efficiency, etc., the respective ratios of Vik component, B component, C component, and D component must be considered. This value is based on the Aa component and the B component. In the relationship, A component/B component = 0.5
~5 is preferably about 2 to 3 (weight ratio) 0 If this weight ratio exceeds 5, the relative 1c B [min. lk will be small, resulting in poor dispersion and sedimentation. In addition, the grain size becomes coarse and a clear kJ image cannot be obtained. On the other hand, if the mt ratio is smaller than 0.5, the dispersion will be excessive and the resistance of the carrier liquid will decrease due to some of the B component leaching out, making it impossible to obtain a high quality liquid developer. The relationship between the components and the C component is (component A + component B)/component C = 0.2 to 2, preferably about 1 (weight ratio). Outside of this range, toner dispersibility and photoreceptor or electrostatic This does not contribute to improving the releasability of the image area toner present on the recording medium.

Further, in the relationship between the A component and the D component, A component/D component = 1 to 4, preferably Fll, 4 to 2.
It is about 5 (weight ratio). If this weight ratio exceeds 4, the image transfer efficiency will decrease, the uniformity of the image density, especially the peta area, will be impaired, and the stability of the Q number will decrease slightly, and vice versa. If the weight ratio is smaller than i, a large amount of component D will be eluted into the carrier liquid, and the viscosity of the developer will increase, which will impede the mechanical efficiency and transfer efficiency. On the other hand, D
When the component is used in combination with the C component, a remarkable MR effect is brought about, but in this case, in the relationship between the C component and the D component, the C component
Component/D component = 0.5-5 preferably 1-2 (weight ratio)
In the liquid developer manufactured by Jin, the toner components are component A, which is substantially insoluble in the carrier liquid, and component B, which has excellent polarity control and good dispersibility in the carrier liquid.
component, C component that further increases dispersibility, D component that increases transfer efficiency and image clarity, and colorant, so that component A is surrounded by component B, component C, and component D. A form has been adopted. Therefore, this 5A
The toner will form a fairly bulky toner image when it is applied to the electrostatic image.

However, some conventional liquid developers are capable of forming bulky toner images. That is, the developer proposed in Japanese Patent Publication No. 54-35492 mentioned earlier is composed of resin particles insoluble in aliphatic hydrocarbons and a specific graft polymer component9. An aromatic hydrocarbon solvent such as toluene is used during IJ-y production, and this aromatic hydrocarbon solvent is contained in the visual liquid as it is. Due to the presence of this aromatic hydrocarbon solvent in the carrier liquid, the surface of the resin particles that are insoluble in the aliphatic hydrocarbon 5pc solvent becomes more soluble and softens over time, making it difficult to obtain bulky images. At the same time, the electrical properties of the toner change, resulting in a satisfactory image.
It has the disadvantage that it does not provide a good level of elasticity, and on the other hand, it increases the staining of the skin. In addition, since the kraft polymer has strong viscosity, the viscosity of the carrier liquid as a whole is high, so it tends to easily adhere to the surface of the grain. This has the disadvantage that the amount of material taken out is also large.

When obtaining a copy image using the developer of the present invention, the above-mentioned bulky toner image is formed and the transferability of this image is good. It is possible to selectively transfer only the image toner to the image-receiving paper. Therefore, the image density is high, and even if the carrier liquid does not adhere to the image-receiving paper, the amount is extremely small, so background stains are prevented. The effect is negligible and the image clarity is excellent.

According to the developer of the present invention, as described above, copies with high density and good clarity can be obtained, but if the C component is omitted, the uniformity of the density in the petal area is insufficient, resulting in the occurrence of scratches. 6. Copy images tend to have a certain image quality. The method for obtaining bulky toner includes (a) forming an electrostatic latent gI on a photoconductor or electrostatic recording medium, and developing it with the developer of the present invention, in the same way as the method that has been used up to now; An image is obtained, and image-receiving paper (for example, plain paper) is applied to the image and transferred. (b) After forming an electrostatic latent image on the photoconductor or electrostatic recording medium, this is developed with the developer of the present invention to obtain a bulky toner image, and then the polarity of the toner is reversed and then the entire surface is exposed. Then, the toner image is transferred by applying a scorotron charger to the image-receiving paper from the noodle side of the image-receiving paper.

Next, examples will be shown.

5ii: Example 1 Zero-gin modified maleic acid resin 1001kIIs Kazen Black (manufactured by Mitsubishi Kasei Corporation, Mitsubishi Color Kazen φ44) 20
A colored resin powder having a volume average particle size of about 4 μm is obtained by kneading the heavy weight part in a heated roll mill, cooling it, and pulverizing it [Component A].
I got it.

On the other hand, Isopar G (manufactured by Esso Standard Oil Co., Ltd.) 300f was placed in a container equipped with a stirrer, a thermometer, and a reflux condenser, and heated to 95°C. In this, 200f of 2-ethylhexyl methacrylate, 10f of glycidyl methacrylate
F, a mixture of 3 t of azobisisobutyronitrile was added dropwise at a constant rate over 3 hours, and the mixture was further stirred for 1 hour to complete the reaction. To this was added acrylic@S t and 0.0 t of hydroquinone. IP and lauryl dimethylamine iF were added and reacted at 90° C. for 20 hours to esterify the copolymer obtained in the reaction. The degree of esterification Fi# is in the range of 25 to 30% from the measurement of the decrease in value.Next, Aitunosel 0500F was added to the esterification reaction solution, and methyl methacrylate 50F and azobisisobutyronitrile 3F were heated at 90°C. was added dropwise over a period of 3 hours at a constant rate, and the liquid temperature was maintained at the above temperature for about 5 hours to complete the reaction, thereby preparing a latex liquid containing 17.5 g of resin [component B]. Furthermore, 300 tons of this reaction product was added with Aitunosel H3O.
After adding 0f, heat to 90℃ and add polyethylene wax 1
00 tTr was added, heated and dissolved for 1 hour until it became transparent, stirred and dispersed, and then cooled. 9-Put it in Lu H100r,
The mixture was stirred for 24 hours to dissolve. Next, 14 parts by weight of the above ingredients -C dispersion liquid 801ii: i part component solution
Disperse 40 weight tm Isobar H150 Fuyutto for 24 hours in a small Zerunle to make a concentrated toner, and dilute this concentrated toner with Aitsunoru G to a solid content of 1.5% to make a 3J image solution. did.

A commercially available electrophotographic copying machine (manufactured by Ricoh, DT-1200)
) was used for copying in which the electrostatic latent image on the S photoreceptor was visually imaged and transferred, and its characteristics were as shown in Nen-1, in particular, the image density was much higher, there was less background staining, and the transfer was easier. The amount of carrier wL (solvent) attached to the paper was small.0Also, after taking this developing solution in a beaker and placing it in an IM mode to allow the toner to settle, simply shaking it lightly will remove the settled toner. redistributed. After one week had elapsed, the developer solution was lightly stirred and then used for copying, and the gI characteristics of the image were the same as those at the early stage.

Example 2 Carne black (Mitsubishi color carzen φ44) 8
A colored resin powder [component A] with a volume average particle diameter of about 7 μm was obtained by mixing the heavy IIS with a heated roll kil, cooling it, and pulverizing it.◇ Meanwhile, a container equipped with a stirrer, thermometer, and reflux condenser was used. The mixture was heated to 95°C. In this, 2-ethylhexyl methacrylate) 200F
Glycidyl methacrylate 8 (1) 3 t of azobisisobutyronitrile was added dropwise at a constant rate over 3 hours to react, and then stirred for about 1 hour to complete the reaction.To this, methacrylic acid 15F,
Hydroquinone 0.1f and lauryl dimethyl aquine!
f was added and reacted at 90°0 for 15 hours to esterify the co-electrolyte obtained in step 1. The degree of esterification was 20 to 30% as determined by the acid value measurement. Isopar H5QOf was added to the esterification reaction solution, and methyl methacrylate 50F and azobisisobutyronitrile 3F were added dropwise at a constant rate over 3 hours at 95°C. After maintaining the liquid temperature at a constant temperature for 5 hours, it was cooled to form a latex ( Resin content 17.5%
) was made with p+ [B component] 0th order l, this allowance is 300
CB-C dispersion by heating and squeezing ethylene wax [component C] and 1SOt into Kari 9 (1), which is made by adding Aitsunoru G300F to V, melting by heating for 1 hour until it becomes transparent, stirring and dispersing, and then cooling] .

In addition, butyl rubber [component D] is finely powdered #tIII and then 7-2
0fffi') A-kH100fcPl, 24
Stir for hours to dissolve.

Next, the above A31) 1511ts above B-
C dispersion now-*b Above component solution 50 weight 1' weight
A concentrated toner was obtained by dispersing 111 parts of Le H110ml in a small L-Lumill for 24 hours, and this concentrated toner was diluted with Aitsunol G to give a solid content of 1.5% to prepare a developer.

When this was used in a commercially available electrophotographic copying machine to visually image and transfer an electrostatic latent image on a Se susceptor, its properties were good as shown in Table 1.

Furthermore, the redispersibility of the toner in this developer was uniformly good as in Example 1. The resin particles [component A] having a volume average particle diameter of about 7.5 μm were obtained.

On the other hand, take Isopar H300f in a three-necked container containing 1 and 6 with a stirrer, a thermometer, and a reflux condenser.
heated to ℃. Also, 2-ethylhexyl methacrylate
) 8Of perakasite P-171 was dissolved in 2001F, and 2f of azobisisobutyronitrile was further mixed therein. This mixture was dropwise polymerized into the container for 4 hours, and then stirred for 1 hour to form a fat with a solid content of 48.3%.
Component B] Make a batch of g and add fco this dispersion 20? and Cardan Black 51. Polyethylene wax 209 and Aitsu no Kami-H100F were dispersed and mixed while heating to 90°C [B-C dispersion].

Also, styrene butadiene rubber (styrene 20 mol%)
After finely powdering (Component D), add 20? of it to Isovar H10.
Next, Component A 13tJ1 part B-C dispersion 80 parts by weight component dissolved i% [6011 parts by weight Dispersion was carried out in I-Lumil for 24 hours to obtain a concentrated toner, and this concentrated toner was diluted with Isovar H to give a solid content of 1.5% to obtain a visual liquid.This was prepared in the same manner as in Example 1. When it was used for copying, its properties were good as shown in Table 1. In addition, the refractionability of the toner of this present liquid was good as in Example 1.

In place of the unsaturated polyester resin in Example 2, a rosin-modified phenol resin (N11!1 manufactured by Kasei Co., Ltd., grade B-1) was used.
45G), and the volume average particle size of component A was approximately 6.7.
A concentrated toner was obtained in the same manner as in Example 2 except that the μ group was used, and this was adjusted to have a solid content of 1.5%.
When the solution was diluted to make a visual liquid and used for copying, its properties were good as shown in Table 1.

Furthermore, the toner redispersibility of this desk image liquid was as good as in Example 1.

Example 5 A concentrated toner was obtained in the same manner as in Example 3, except that % of an unsaturated polyester resin (Atrac 382E, manufactured by Kako Atlas Co., Ltd.) was used in place of the styrene-n-butyl methacrylate copolymer in Example 3. When this was diluted with Isovar H to give a solid content of 1.5% and used for copying, the properties obtained were good as shown in Table 1.

Claims (1)

[Claims] 1. In a carrier liquid of petroleum-based aliphatic hydrocarbon, resin particles (component A) that are substantially insoluble in the carrier liquid, and resin obtained by suspension polymerization in the carrier liquid (component B). , wax or polyolefin resin particles (component C) and a rubber-based resin soluble in the carrier liquid (component D) are dispersed, and the weight ratio of these components A and B is 0.5 to 5, The weight ratio of the sum of A component and B component to C component is in the range of 0.2 to 2, the weight ratio of A component to D component is in the range of 1 to 40), and the colorant is at least A component or B component. %
Moldy liquid developer for electrostatic images 0